lkml.org 
[lkml]   [2009]   [Feb]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: find nr_irqs_gsi with mp_ioapic_routing


> >> Impact: find right nr_irqs_gsi on some systems.
> >>
> >> one system has gap between gsi.
> >> [ 0.000000] ACPI: IOAPIC (id[0x04] address[0xfec00000] gsi_base[0])
> >> [ 0.000000] IOAPIC[0]: apic_id 4, version 0, address 0xfec00000, GSI 0-23
> >> [ 0.000000] ACPI: IOAPIC (id[0x05] address[0xfeafd000] gsi_base[48])
> >> [ 0.000000] IOAPIC[1]: apic_id 5, version 0, address 0xfeafd000, GSI 48-54
> >> [ 0.000000] ACPI: IOAPIC (id[0x06] address[0xfeafc000] gsi_base[56])
> >> [ 0.000000] IOAPIC[2]: apic_id 6, version 0, address 0xfeafc000, GSI 56-62
> >> ...
> >> [ 0.000000] nr_irqs_gsi: 38
> >
> > I've never seen gaps in GSIs.
> > I've never seen IOAPICs with 7 redirection table entries.
> >
> > This system looks quite broken even before the probe for nr_irqs_gsi.
> > Do you have more information on it?
>
> it is one AMD based system from Sun.
> it has two hypertransport chains.
> one: 8132 + ck804
> one: io4
>
> when 8 sockets are installed, will get
> [ 0.000000] ACPI: IOAPIC (id[0x00] address[0xfec00000] gsi_base[0])
> [ 0.000000] IOAPIC[0]: apic_id 0, version 0, address 0xfec00000, GSI 0-23
> [ 0.000000] ACPI: IOAPIC (id[0x01] address[0xfdefd000] gsi_base[48])
> [ 0.000000] IOAPIC[1]: apic_id 1, version 0, address 0xfdefd000, GSI 48-54
> [ 0.000000] ACPI: IOAPIC (id[0x02] address[0xfdefc000] gsi_base[56])
> [ 0.000000] IOAPIC[2]: apic_id 2, version 0, address 0xfdefc000, GSI 56-62
> [ 0.000000] ACPI: IOAPIC (id[0x03] address[0xfeaff000] gsi_base[24])
> [ 0.000000] IOAPIC[3]: apic_id 3, version 0, address 0xfeaff000, GSI 24-47
>
>
> when 2 sockets are installed, only HT chains is used. will get
> [ 0.000000] ACPI: IOAPIC (id[0x04] address[0xfec00000] gsi_base[0])
> [ 0.000000] IOAPIC[0]: apic_id 4, version 0, address 0xfec00000, GSI 0-23
> [ 0.000000] ACPI: IOAPIC (id[0x05] address[0xfeafd000] gsi_base[48])
> [ 0.000000] IOAPIC[1]: apic_id 5, version 0, address 0xfeafd000, GSI 48-54
> [ 0.000000] ACPI: IOAPIC (id[0x06] address[0xfeafc000] gsi_base[56])
> [ 0.000000] IOAPIC[2]: apic_id 6, version 0, address 0xfeafc000, GSI 56-62
>
> acpi madt ioapic-entries does include gsi_base field.
>
> amd 8131: has 4 gsi
> amd 8132: has 7 gsi, but only 3 can be used.
>
> anyway that system is not broken, and it is quite solid.

I don't know if it violates the ACPI spec to have gaps in the GSI's,
but it does violate my expectations when I read the spec -- so i guess
that "unexpected" or "unconventional" may be a better word than "broken".

At the same time, "unexpected" and "unconventional" BIOS implementations
cause things like "broken" OS -- thus the need for your patch:-)

> this patch seems to be a 2.6.29 material.

I agree.

thanks,
Len Brown, Intel Open Source Technology Center



\
 
 \ /
  Last update: 2009-02-07 08:19    [W:0.060 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site